Wireless communication method for transmitting ACK and wireless communication terminal using same

ABSTRACT

Provided is a wireless communication terminal that communicates wirelessly. The wireless communication terminal includes a transceiver, and a processor. The processor is configured to receive an Aggregate-MAC Protocol Data Unit (A-MPDU) from an originator using the transceiver, and when receiving all MPDUs included in the A-MPDU, transmit to the originator a block ACK (BA) frame signaling that all MPDUs included in the A-MPDU are received without a bitmap indicating whether each MPDU included in the A-MPDU is received.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/KR2017/004888 filed on May 11, 2017, which claims the priorityto Korean Patent Application No. 10-2016-0057759 filed in the KoreanIntellectual Property Office on May 11, 2016, Korean Patent ApplicationNo. 10-2016-0074090 filed in the Korean Intellectual Property Office onJun. 14, 2016, and Korean Patent Application No. 10-2016-0093811 filedin the Korean Intellectual Property Office on Jul. 23, 2016, the entirecontents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a wireless communication method and awireless communication terminal for transmitting ACK.

BACKGROUND ART

In recent years, with supply expansion of mobile apparatuses, a wirelesscommunication technology that can provide a rapid wireless Internetservice to the mobile apparatuses has been significantly spotlighted.The wireless communication technology allows mobile apparatusesincluding a smart phone, a smart pad, a laptop computer, a portablemultimedia player, an embedded apparatus, and the like to wirelesslyaccess the Internet in home or a company or a specific service providingarea.

One of most famous wireless communication technology is wireless LANtechnology. Institute of Electrical and Electronics Engineers (IEEE)802.11 has commercialized or developed various technological standardssince an initial wireless LAN technology is supported using frequenciesof 2.4 GHz. First, the IEEE 802.11b supports a communication speed of amaximum of 11 Mbps while using frequencies of a 2.4 GHz band. IEEE802.11a which is commercialized after the IEEE 802.11b uses frequenciesof not the 2.4 GHz band but a 5 GHz band to reduce an influence byinterference as compared with the frequencies of the 2.4 GHz band whichare significantly congested and improves the communication speed up to amaximum of 54 Mbps by using an Orthogonal Frequency DivisionMultiplexing (OFDM) technology. However, the IEEE 802.11a has adisadvantage in that a communication distance is shorter than the IEEE802.11b. In addition, IEEE 802.11g uses the frequencies of the 2.4 GHzband similarly to the IEEE 802.11b to implement the communication speedof a maximum of 54 Mbps and satisfies backward compatibility tosignificantly come into the spotlight and further, is superior to theIEEE 802.11a in terms of the communication distance.

Moreover, as a technology standard established to overcome a limitationof the communication speed which is pointed out as a weak point in awireless LAN, IEEE 802.11n has been provided. The IEEE 802.11n aims atincreasing the speed and reliability of a network and extending anoperating distance of a wireless network. In more detail, the IEEE802.11n supports a high throughput (HT) in which a data processing speedis a maximum of 540 Mbps or more and further, is based on a multipleinputs and multiple outputs (MIMO) technology in which multiple antennasare used at both sides of a transmitting unit and a receiving unit inorder to minimize a transmission error and optimize a data speed.Further, the standard can use a coding scheme that transmits multiplecopies which overlap with each other in order to increase datareliability.

As the supply of the wireless LAN is activated and further, applicationsusing the wireless LAN are diversified, the need for new wireless LANsystems for supporting a higher throughput (very high throughput (VHT))than the data processing speed supported by the IEEE 802.11n has comeinto the spotlight. Among them, IEEE 802.11ac supports a wide bandwidth(80 to 160 MHz) in the 5 GHz frequencies. The IEEE 802.11ac standard isdefined only in the 5 GHz band, but initial 11 ac chipsets will supporteven operations in the 2.4 GHz band for the backward compatibility withthe existing 2.4 GHz band products. Theoretically, according to thestandard, wireless LAN speeds of multiple stations are enabled up to aminimum of 1 Gbps and a maximum single link speed is enabled up to aminimum of 500 Mbps. This is achieved by extending concepts of awireless interface accepted by 802.11n, such as a wider wirelessfrequency bandwidth (a maximum of 160 MHz), more MIMO spatial streams (amaximum of 8), multi-user MIMO, and high-density modulation (a maximumof 256 QAM). Further, as a scheme that transmits data by using a 60 GHzband instead of the existing 2.4 GHz/5 GHz, IEEE 802.11ad has beenprovided. The IEEE 802.11ad is a transmission standard that provides aspeed of a maximum of 7 Gbps by using a beamforming technology and issuitable for high bit rate moving picture streaming such as massive dataor non-compression HD video. However, since it is difficult for the 60GHz frequency band to pass through an obstacle, it is disadvantageous inthat the 60 GHz frequency band can be used only among devices in ashort-distance space.

Meanwhile, in recent years, as next-generation wireless communicationtechnology standards after the 802.11ac and 802.11ad, discussion forproviding a high-efficiency and high-performance wireless communicationtechnology in a high-density environment is continuously performed. Thatis, in a next-generation wireless communication technology environment,communication having high frequency efficiency needs to be providedindoors/outdoors under the presence of high-density terminals and baseterminals and various technologies for implementing the communicationare required.

Especially, as the number of devices using a wireless communicationtechnology increases, it is necessary to efficiently use a predeterminedchannel Therefore, required is a technology capable of efficiently usingbandwidths by simultaneously transmitting data between a plurality ofterminals and base terminals.

DISCLOSURE Technical Problem

An object of an embodiment of the present invention is to provide awireless communication terminal for transmitting ACK.

Technical Solution

According to the present invention, provided is a wireless communicationterminal that is a recipient for receiving data, the terminal including:a transceiver; and a processor. The processor is configured to receivean Aggregate-MAC Protocol Data Unit (A-MPDU) from an originator usingthe transceiver, and when receiving all MPDUs included in the A-MPDU,transmit to the originator a block ACK (BA) frame signaling that allMPDUs included in the A-MPDU are received without a bitmap indicatingwhether each MPDU included in the A-MPDU is received.

The processor may be configured to set a predetermined first value in atraffic identifier (TID) field of the BA frame when transmitting the BAframe. The TID field may indicate a TID of an MPDU, in which the MPDU isreceived by the BA frame.

The predetermined first value may be a value that is not used as a TIDvalue in data transmission.

The processor may be configured to omit a start sequence control fieldwhen transmitting the BA frame. The start sequence control field may befor indicating an MPDU, in which whether the MPDU is received indicatedby the bitmap.

When transmitting the BA frame, the processor may be configured to set avalue of an ACK type field indicating a type of an ACK in the BA frameto a predetermined second value to indicate that the bitmap and thestart sequence control field are not included.

The A-MPDU may include a plurality of MPDUs corresponding to a pluralityof different TIDs.

When transmitting the BA frame, the processor may be configured to set avalue of an ACK type field indicating a type of an ACK in the BA frameto a predetermined value, and may set a TID value agreed on BA frametransmission with the originator in a TID field of the BA frame. Thetraffic identifier (TID) field may indicate a TID of an MPDU, in whichwhether the MPDU is received by the BA frame.

When a TID agreed on BA frame transmission with the originator is inplurality, the processor may be configured to set a value of a TID fieldof the BA frame based on a user priority of a TID.

According to the present invention, provided is a wireless communicationterminal that is an originator for transmitting data, the terminalincluding: a transceiver; and a processor. The processor may beconfigured to transmit an Aggregate-MAC Protocol Data Unit (A-MPDU) to arecipient using the transceiver, and receive a block ACK (BA) frame fromthe recipient. The BA frame may indicate that all MPDUs included in theA-MPDU are received without a bitmap indicating whether each MPDUincluded in the A-MPDU is received.

When a value of a traffic identifier (TID) field of the BA frame is apredetermined first value, the processor may be configured to determinethat the BA frame indicates that all MPDUs included in the A-MPDU arereceived without a bitmap indicating whether each MPDU included in theA-MPDU is received. The TID field may indicate a TID of an MPDU, inwhich whether the MPDU is received is indicated by the BA frame.

The predetermined first value may be a value that is not used as a TIDvalue in data transmission.

The BA frame may not include a start sequence control field which is forindicating an MPDU, in which whether the MPDU is received indicated bythe bitmap.

When a value of the TID field of the BA frame is a predetermined firstvalue and a value of an ACK type field of the BA frame is apredetermined second value, the processor may be configured to determinethat the BA frame indicates that all MPDUs included in the A-MPDU arereceived without a bitmap indicating whether each MPDU included in theA-MPDU is received. The ACK type field may indicate a type of an ACK.

The A-MPDU may include a plurality of MPDUs corresponding to a pluralityof different TIDs.

According to the present invention, provided is an operation method of awireless communication terminal that is a recipient for receiving data,the method including: receiving an Aggregate-MAC Protocol Data Unit(A-MPDU) from an originator; and when receiving all MPDUs included inthe A-MPDU, transmitting to the originator a block ACK (BA) framesignaling that all MPDUs included in the A-MPDU are received without abitmap indicating whether each MPDU included in the A-MPDU is received.

The transmitting the BA frame may include configuring a predeterminedfirst value in a traffic identifier (TID) field of the BA frame whentransmitting the BA frame. The TID field may indicate a TID of an MPDU,in which whether the MPDU is received is indicated by the BA frame.

The predetermined first value may be a value that is not used as a TIDvalue in data transmission.

The transmitting the BA frame may further include omitting a startsequence control field when transmitting the BA frame. The startsequence control field may be for indicating an MPDU, in which whetherthe MPDU is received indicated by the bitmap.

The omitting he start sequence control field may include, whentransmitting the BA frame, setting a value of an ACK type fieldindicating a type of an ACK in the BA frame to a predetermined secondvalue to indicate that the bitmap and the start sequence control fieldare not included.

The A-MPDU may include a plurality of MPDUs corresponding to a pluralityof different TIDs.

Advantageous Effects

An embodiment of the present invention provides a wireless communicationmethod for transmitting ACK and wireless communication terminal usingthe same.

DESCRIPTION OF DRAWINGS

FIG. 1 shows a wireless LAN system according to an embodiment of thepresent invention.

FIG. 2 shows a wireless LAN system according to another embodiment ofthe present invention.

FIG. 3 shows a block diagram illustrating a configuration of a stationaccording to an embodiment of the inventive concept.

FIG. 4 shows a block diagram illustrating a configuration of an accesspoint according to an embodiment of the present invention.

FIG. 5 shows a process that a station sets an access point and a linkaccording to an embodiment of the present invention.

FIG. 6 shows a method for transmitting a Block ACK (BA) frame for anAggregate-MAC Protocol Data Unit (A-MPDU) according to an embodiment ofthe present invention.

FIG. 7 shows that a wireless communication terminal transmits an A-MPDUwith multiple TIDs according to an embodiment of the present invention.

FIG. 8 shows a format of a Multi-STA Block ACK frame according to anembodiment of the present invention.

FIG. 9 shows a method of transmitting an M-BA frame by a wirelesscommunication terminal according to an embodiment of the presentinvention.

FIG. 10 shows a method of transmitting an M-BA frame by a wirelesscommunication terminal according to an embodiment of the presentinvention.

FIG. 11 shows a method of transmitting an M-BA frame by a wirelesscommunication terminal according to another embodiment of the presentinvention.

FIG. 12 shows a method of transmitting an M-BA frame by a wirelesscommunication terminal according to another embodiment of the presentinvention.

FIG. 13 shows a method of transmitting an M-BA frame by a wirelesscommunication terminal according to another embodiment of the presentinvention.

FIG. 14 shows an operation in which a wireless communication terminaltransmits a BSR according to an embodiment of the present invention.

FIG. 15 shows an operation in which a wireless communication terminaltransmits a BSR according to another embodiment of the presentinvention.

FIG. 16 shows an operation in which a wireless communication terminaltransmits a BSR according to another embodiment of the presentinvention.

FIG. 17 shows an operation in which a wireless communication terminaltransmits a BSR according to another embodiment of the presentinvention.

FIG. 18 shows the operation of a wireless communication terminalaccording to an embodiment of the present invention.

MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention will be described belowin more detail with reference to the accompanying drawings. The presentinvention may, however, be embodied in different forms and should not beconstructed as limited to the embodiments set forth herein. Parts notrelating to description are omitted in the drawings in order to clearlydescribe the present invention and like reference numerals refer to likeelements throughout.

Furthermore, when it is described that one comprises (or includes orhas) some elements, it should be understood that it may comprise (orinclude or has) only those elements, or it may comprise (or include orhave) other elements as well as those elements if there is no specificlimitation.

This application claims priority to and the benefit of Korean PatentApplication Nos. 10-2016-0057759 (2016.05.11), Nos. 10-2016-0074090(2016.06.14), and Nos. 10-2016-0093811 (2016.07.23) filed in the KoreanIntellectual Property Office and the embodiments and mentioned itemsdescribed in the respective applications are included in the DetailedDescription of the present application.

FIG. 1 is a diagram illustrating a wireless communication systemaccording to an embodiment of the present invention. For convenience ofdescription, an embodiment of the present invention is described throughthe wireless LAN system. The wireless LAN system includes one or morebasic service sets (BSS) and the BSS represents a set of apparatuseswhich are successfully synchronized with each other to communicate witheach other. In general, the BSS may be classified into an infrastructureBSS and an independent BSS (IBSS) and FIG. 1 illustrates theinfrastructure BSS between them.

As illustrated in FIG. 1 , the infrastructure BSS (BSS1 and BSS2)includes one or more stations STA1, STA2, STA3, STA4, and STA5, accesspoints PCP/AP-1 and PCP/AP-2 which are stations providing a distributionservice, and a distribution system (DS) connecting the multiple accesspoints PCP/AP-1 and PCP/AP-2.

The station (STA) is a predetermined device including medium accesscontrol (MAC) following a regulation of an IEEE 802.11 standard and aphysical layer interface for a wireless medium, and includes both anon-access point (non-AP) station and an access point (AP) in a broadsense. Further, in the present specification, a term ‘terminal’ may beused to refer to a concept including a wireless LAN communication devicesuch as non-AP STA, or an AP, or both terms. A station for wirelesscommunication includes a processor and a transceiver and according tothe embodiment, may further include a user interface unit and a displayunit. The processor may generate a frame to be transmitted through awireless network or process a frame received through the wirelessnetwork and besides, perform various processing for controlling thestation. In addition, the transceiver is functionally connected with theprocessor and transmits and receives frames through the wireless networkfor the station.

The access point (AP) is an entity that provides access to thedistribution system (DS) via wireless medium for the station associatedtherewith. In the infrastructure BSS, communication among non-APstations is, in principle, performed via the AP, but when a direct linkis configured, direct communication is enabled even among the non-APstations. Meanwhile, in the present invention, the AP is used as aconcept including a personal BSS coordination point (PCP) and mayinclude concepts including a centralized controller, a base station(BS), a node-B, a base transceiver system (BTS), and a site controllerin a broad sense.

A plurality of infrastructure BSSs may be connected with each otherthrough the distribution system (DS). In this case, a plurality of BSSsconnected through the distribution system is referred to as an extendedservice set (ESS).

FIG. 2 illustrates an independent BSS which is a wireless communicationsystem according to another embodiment of the present invention. Forconvenience of description, another embodiment of the present inventionis described through the wireless LAN system. In the embodiment of FIG.2 , duplicative description of parts, which are the same as orcorrespond to the embodiment of FIG. 1 , will be omitted.

Since a BSS3 illustrated in FIG. 2 is the independent BSS and does notinclude the AP, all stations STA6 and STA7 are not connected with theAP. The independent BSS is not permitted to access the distributionsystem and forms a self-contained network. In the independent BSS, therespective stations STA6 and STA7 may be directly connected with eachother.

FIG. 3 is a block diagram illustrating a configuration of a station 100according to an embodiment of the present invention.

As illustrated in FIG. 3 , the station 100 according to the embodimentof the present invention may include a processor 110, a transceiver 120,a user interface unit 140, a display unit 150, and a memory 160.

First, the transceiver 120 transmits and receives a wireless signal suchas a wireless LAN physical layer frame, or the like and may be embeddedin the station 100 or provided as an exterior. According to theembodiment, the transceiver 120 may include at least one transmit andreceive module using different frequency bands. For example, thetransceiver 120 may include transmit and receive modules havingdifferent frequency bands such as 2.4 GHz, 5 GHz, and 60 GHz. Accordingto an embodiment, the station 100 may include a transmit and receivemodule using a frequency band of 6 GHz or more and a transmit andreceive module using a frequency band of 6 GHz or less. The respectivetransmit and receive modules may perform wireless communication with theAP or an external station according to a wireless LAN standard of afrequency band supported by the corresponding transmit and receivemodule. The transceiver 120 may operate only one transmit and receivemodule at a time or simultaneously operate multiple transmit and receivemodules together according to the performance and requirements of thestation 100. When the station 100 includes a plurality of transmit andreceive modules, each transmit and receive module may be implemented byindependent elements or a plurality of modules may be integrated intoone chip.

Next, the user interface unit 140 includes various types of input/outputmeans provided in the station 100. That is, the user interface unit 140may receive a user input by using various input means and the processor110 may control the station 100 based on the received user input.Further, the user interface unit 140 may perform output based on acommand of the processor 110 by using various output means.

Next, the display unit 150 outputs an image on a display screen. Thedisplay unit 150 may output various display objects such as contentsexecuted by the processor 110 or a user interface based on a controlcommand of the processor 110, and the like. Further, the memory 160stores a control program used in the station 100 and various resultingdata. The control program may include an access program required for thestation 100 to access the AP or the external station.

The processor 110 of the present invention may execute various commandsor programs and process data in the station 100. Further, the processor110 may control the respective units of the station 100 and control datatransmission/reception among the units. According to the embodiment ofthe present invention, the processor 110 may execute the program foraccessing the AP stored in the memory 160 and receive a communicationconfiguration message transmitted by the AP. Further, the processor 110may read information on a priority condition of the station 100 includedin the communication configuration message and request the access to theAP based on the information on the priority condition of the station100. The processor 110 of the present invention may represent a maincontrol unit of the station 100 and according to the embodiment, theprocessor 110 may represent a control unit for individually controllingsome component of the station 100, for example, the transceiver 120, andthe like. The processor 110 may be a modulator and/or demodulator whichmodulates wireless signal transmitted to the transceiver 120 anddemodulates wireless signal received from the transceiver 120. Theprocessor 110 controls various operations of wireless signaltransmission/reception of the station 100 according to the embodiment ofthe present invention. A detailed embodiment thereof will be describedbelow.

The station 100 illustrated in FIG. 3 is a block diagram according to anembodiment of the present invention, where separate blocks areillustrated as logically distinguished elements of the device.Accordingly, the elements of the device may be mounted in a single chipor multiple chips depending on design of the device. For example, theprocessor 110 and the transceiver 120 may be implemented while beingintegrated into a single chip or implemented as a separate chip.Further, in the embodiment of the present invention, some components ofthe station 100, for example, the user interface unit 140 and thedisplay unit 150 may be optionally provided in the station 100.

FIG. 4 is a block diagram illustrating a configuration of an AP 200according to an embodiment of the present invention.

As illustrated in FIG. 4 , the AP 200 according to the embodiment of thepresent invention may include a processor 210, a transceiver 220, and amemory 260. In FIG. 4 , among the components of the AP 200, duplicativedescription of parts which are the same as or correspond to thecomponents of the station 100 of FIG. 2 will be omitted.

Referring to FIG. 4 , the AP 200 according to the present inventionincludes the transceiver 220 for operating the BSS in at least onefrequency band. As described in the embodiment of FIG. 3 , thetransceiver 220 of the AP 200 may also include a plurality of transmitand receive modules using different frequency bands. That is, the AP 200according to the embodiment of the present invention may include two ormore transmit and receive modules among different frequency bands, forexample, 2.4 GHz, 5 GHz, and 60 GHz together. Preferably, the AP 200 mayinclude a transmit and receive module using a frequency band of 6 GHz ormore and a transmit and receive module using a frequency band of 6 GHzor less. The respective transmit and receive modules may performwireless communication with the station according to a wireless LANstandard of a frequency band supported by the corresponding transmit andreceive module. The transceiver 220 may operate only one transmit andreceive module at a time or simultaneously operate multiple transmit andreceive modules together according to the performance and requirementsof the AP 200.

Next, the memory 260 stores a control program used in the AP 200 andvarious resulting data. The control program may include an accessprogram for managing the access of the station. Further, the processor210 may control the respective units of the AP 200 and control datatransmission/reception among the units. According to the embodiment ofthe present invention, the processor 210 may execute the program foraccessing the station stored in the memory 260 and transmitcommunication configuration messages for one or more stations. In thiscase, the communication configuration messages may include informationabout access priority conditions of the respective stations. Further,the processor 210 performs an access configuration according to anaccess request of the station. The processor 210 may be a modulatorand/or demodulator which modulates wireless signal transmitted to thetransceiver 220 and demodulates wireless signal received from thetransceiver 220. The processor 210 controls various operations such asradio signal transmission/reception of the AP 200 according to theembodiment of the present invention. A detailed embodiment thereof willbe described below.

FIG. 5 is a diagram schematically illustrating a process in which a STAsets a link with an AP.

Referring to FIG. 5 , the link between the STA 100 and the AP 200 is setthrough three steps of scanning, authentication, and association in abroad way. First, the scanning step is a step in which the STA 100obtains access information of BSS operated by the AP 200. A method forperforming the scanning includes a passive scanning method in which theAP 200 obtains information by using a beacon message (S101) which isperiodically transmitted and an active scanning method in which the STA100 transmits a probe request to the AP (S103) and obtains accessinformation by receiving a probe response from the AP (S105).

The STA 100 that successfully receives wireless access information inthe scanning step performs the authentication step by transmitting anauthentication request (S107 a) and receiving an authentication responsefrom the AP 200 (S107 b). After the authentication step is performed,the STA 100 performs the association step by transmitting an associationrequest (S109 a) and receiving an association response from the AP 200(S109 b).

Meanwhile, an 802.1X based authentication step (S111) and an IP addressobtaining step (S113) through DHCP may be additionally performed. InFIG. 5 , the authentication server 300 is a server that processes 802.1Xbased authentication with the STA 100 and may be present in physicalassociation with the AP 200 or present as a separate server.

In a specific embodiment, the AP 200 may be a wireless communicationterminal that allocates a communication medium resource and performsscheduling in an independent network, such as an ad-hoc network, whichis not connected to an external distribution service. In addition, theAP 200 may be at least one of a base station, an eNB, and a transmissionpoint TP. The AP 200 may also be referred to as a base wirelesscommunication terminal.

FIG. 6 shows a method for transmitting a Block ACK (BA) frame for anAggregate-MAC Protocol Data Unit (A-MPDU) according to an embodiment ofthe present invention.

The wireless communication terminal may aggregate a plurality of MPDUsto generate one A-MPDU. The wireless communication terminal may transmitthe generated A-MPDU. The legacy wireless communication terminalaggregates only the MPDUs having the same traffic identifier (TID) togenerate the A-MPDU. The wireless communication terminal according tothe embodiment of the present invention may aggregate a plurality ofMPDUs having different TIDs to generate one A-MPDU. For convenience ofexplanation, an A-MPDU including a plurality of MPDUs corresponding to aplurality of different TIDs is referred to as a Multi-TID A-MPDU or anA-MPDU with Multiple TIDs. The wireless communication terminal maytransmit the A-MPDU more flexibly through it. Specifically, a wirelesscommunication terminal may transmit an A-MPDU with multiple TIDs using aPhysical Layer Protocol Data Unit (HE PPDU). In this case, the HE PPDUmay be an HE Multi User (MU) PPDU. Also, the HE PPDU may be an HEtrigger-based PPDU.

The wireless communication terminal may set parameters related to A-MPDUand BA frame transmission in a link setup procedure. The wirelesscommunication terminal may set parameters related to transmission of anA-MPDU with multiple TIDs in the link setup procedure. Specifically, thewireless communication terminal may transmit the maximum TID numberinformation indicating the maximum number of TIDs that the wirelesscommunication terminal may simultaneously receive in the link setupprocedure. In this case, the wireless communication terminal maytransmit the maximum TID number information using the HE capabilityinformation element indicating the capability of the terminal. This isbecause as the number of TIDs of an A-MPDU with Multiple TIDs increases,the high processing capability of the wireless communication terminalreceiving the A-MPDU may be required. The maximum TID number informationmay be the maximum number of TID fields of the HE capability informationelement. The maximum TID number information transmitted by the AP to thenon-AP wireless communication terminal may indicate the maximum TIDnumber that the MPDU included in the UpLink (UL) A-MPDU transmitted bythe corresponding non-AP wireless communication terminal may have. Inaddition, the maximum TID number information transmitted by the non-APwireless communication terminal to the AP may indicate the maximum TIDnumber that the DownLink (DL) A-MPDU transmitted by the corresponding APmay have. In the link setup procedure, the wireless communicationterminal may transmit the maximum TID number information using themanagement frame. In this case, the management frame may be at least oneof a probe request frame, a probe response frame, an authenticationrequest frame, an authentication response frame, an association requestframe, an association response frame, and a beacon frame. Also, when theAP transmits the maximum TID number information using the beacon frame,the maximum TID number information may indicate the TID number that theAP may simultaneously receive. Specifically, when an AP transmits amaximum TID number information using a beacon frame, the maximum TIDnumber information may indicate the maximum TID number that is allowedto be transmitted in the MU UL transmission, not the maximum TID numberthat the MPDU included in the A-MPDU transmitted from any one wirelesscommunication terminal to the AP may have. This is because the APtransmits the beacon frame to the entire wireless communication terminalof the BSS operated by the AP. In another specific embodiment, themaximum TID number information of the beacon frame may be used for otherpurposes. In another specific embodiment, the maximum number of TIDfield of the beacon frame may be a reserved field.

In the link setup procedure, the wireless communication terminal maytransmit an All ACK capable indicator indicating whether the wirelesscommunication terminal may process All ACKs. In this case, the All ACKindicates that the wireless communication terminal signals that all theMPDUs included in the A-MPDU received from the originator are received.Specifically, the wireless communication terminal may transmit an AllACK capable indicator indicating whether the All ACK may be processedusing the HE capability information element.

The wireless communication terminal may fragment and transmit at leastone of a MAC service data unit (MSDU), an Aggregate (A)-MSDU, and amanagement protocol data unit (MMPDU). For convenience of explanation, aportion of an MSDU, a portion of an A-MSDU, or a portion of an MMPDU,which are generated through fragmentation, is referred to as a fragment.In addition, a wireless communication terminal that transmits data isreferred to as an originator, and a wireless communication terminal thatreceives data is referred to as a recipient.

Specifically, the wireless communication terminal may generate aplurality of fragments by fragmenting at least one of an MSDU, anA-MSDU, and an MMPDU. In this case, the wireless communication terminalmay transmit the generated plurality of fragments to a plurality ofMPDUs. In addition, the wireless communication terminal receiving aplurality of fragments may defragment a plurality of fragments to obtainat least one of one MSDU, one A-MSDU, and one MMPDU. In this case, theMPDU may be an S-MPDU or an A-MPDU.

The recipient needs sufficient buffer capacity and processing capacityto defragment multiple fragments. Specifically, the recipient isrequired to store all fragments until the recipient receives all thefragments of the MSDU corresponding to the same sequence number. Thus,when the recipient supports the capability to receive fragments, theoriginator may transmit the fragments to the recipient. Eventually, theoriginator is required to know the fragmentation level that therecipient supports. In this case, the fragmentation level indicates thefragmentation degree that the wireless communication terminal mayreceive. The wireless communication terminal may signal for thefragmentation level. Specifically, the wireless communication terminaltransmits information on the fragmentation level of the fragments thatthe wireless communication terminal may receive in the link setupprocedure with the AP, and receives information on the fragmentationlevel of the fragments that the AP may receive. Specifically, thewireless communication terminal may transmit information on thefragmentation level using the HE Capability information element. In thiscase, the HE Capability information element may indicate the capabilityof the wireless communication terminal. Further, the wirelesscommunication terminal may transmit information on the fragmentationlevel through at least one of a probe request frame, a probe responseframe, an authentication request frame, an authentication responseframe, an association request frame, and an association response frame.

In addition, the fragmentation level may be divided into four levels.Level 0 may indicate that the wireless communication terminal does notsupport fragmentation for the MSDU the wireless communication terminalreceives. Also, level 1 may indicate that the wireless communicationterminal may be capable of receiving an MPDU that includes one fragment.In this case, the MPDU may be a single MPDU that is not aggregated withanother MPDU, or an MPDU that is not an A-MPDU. Also, level 2 mayindicate that the wireless communication terminal may receive an A-MPDUthat includes one fragment per MSDU. Specifically, level 2 may indicatethat the wireless communication terminal may be capable of receiving anA-MPDU that includes one or fewer fragments per MSDU. Level 3 mayindicate that the wireless communication terminal may receive an A-MPDUincluding a plurality of fragments per MSDU. Specifically, level 3 mayindicate that the wireless communication terminal may be capable ofreceiving an A-MPDU including four or fewer fragments per MSDU.

As described above, the HE capability information element may include aMax number of TID field, an All ACK capable indicator, and information(Fragmentation support level) indicating a fragmentation level supportedby the wireless communication terminal. The specific format of the HEcapability information element may be the same as that of the embodimentof FIG. 6 .

Further, the wireless communication terminal may set BA parameters inthe Add Block ACK (ADDBA) procedure. In this case, the BA parameter is aparameter used for BA frame transmit and BA frame reception. Thewireless communication terminal may request an ACK in the form of a BAframe using an ADDBA request frame. Also, the wireless communicationterminal may transmit a response to the ADDBA request frame using theADDBA response frame. The ADDBA request frame and the ADDBA responseframe may include a Block Ack Parameter Set element. In this case, theBlock Ack Parameter Set element includes information on the BAparameter. In addition, the wireless communication terminal may set BAparameters for each TID. Specifically, the wireless communicationterminal may negotiate the BA parameter set-up for each TID. In aspecific embodiment, the wireless communication terminal may specify aTID that is the subject of the BA parameter set-up negotiation using theTID field included in the Block Ack Parameter Set element. Theoriginator may request the BA parameter configuration by transmitting anADDBA request frame. The recipient may receive the ADDBA request frameand transmit the ADDBA response frame for the ADDBA request frame todetermine the BA parameter set-up. If the originator receives an ADDBAresponse frame and transmits an ACK frame for the ADDBA response frame,the originator and recipient may set the BA parameters.

The wireless communication terminal may transmit buffer size informationindicating the number of MPDUs that may be stored until transmitting theBA frame after receiving the data in the ADDBA procedure. Specifically,the wireless communication terminal may transmit the buffer sizeinformation using the Block Ack Parameter Set element in the ADDBAprocedure. The wireless communication terminal may set the length of theBA bitmap based on a range of values that the buffer size informationmay have. Specifically, when the range of the value that the buffer sizeinformation may have is between 1 and X, the wireless communicationterminal may set the length of the BA bitmap to X bits. In this case,when the wireless communication terminal fails to receive information onthe length of the BA bitmap, the wireless communication terminal may setthe length of the BA bitmap to X bits. The specific format of the BlockAck Parameter Set element may be the same as that of the embodiment ofFIG. 6 .

When the AP performs DL transmission to the wireless communicationterminal, the AP may transmit the A-MPDU based on the capability of thewireless communication terminal signaled in the link setup procedure andthe BA parameter set in the ADDBA procedure. In this case, the wirelesscommunication terminal may transmit a BA frame or a Multi-STA Block ACK(M-BA) frame to the AP based on the capability of the AP and the BAparameter set in the ADDBA procedure. A specific format of the BA framewill be described with reference to FIG. 8 .

When the AP simultaneously receives A-MPDUs from a plurality of wirelesscommunication terminals, the AP may be difficult to store a plurality ofMPDUs received by the AP in a buffer and maintain a score board. In thiscase, the score board indicates information on the reception status ofeach of the MPDUs recorded by the AP. Therefore, the AP may use thetrigger frame to indicate the maximum TID number that the A-MPDU to betransmitted by each wireless communication terminal is capable ofhaving. Specifically, the AP may use the Per User Info field of thetrigger frame to indicate the maximum TID to be transmitted by eachwireless communication terminal. In this case, the wirelesscommunication terminal receiving the trigger frame may set the number ofTIDs that the A-MPDU is capable of having based on the trigger frame.Specifically, the wireless communication terminal receiving the triggerframe may configure the TID number of the MPDU included in the A-MPDU totransmit based on the maximum TID number indicated by the trigger frame,and transmit the A-MPDU to the AP. For example, the wirelesscommunication terminal receiving the trigger frame may set the TIDnumber of the MPDU included in the A-MPDU to transmit so as not toexceed the maximum TID number indicated by the trigger frame, andtransmit the A-MPDU to the AP.

In addition, when the wireless communication terminal uses the HE MUPPDU in the Single User (SU) Uplink (UL) transmission, the wirelesscommunication terminal may be not allowed that the wirelesscommunication terminal transmits the A-MPDU with multiple TIDs. Thewireless communication terminal may use a relatively wide transmissionrange in a narrow frequency band using the HE MU PPDU in SU ULtransmission. In this case, if the wireless communication terminal isallowed to transmit the A-MPDU including the A-MPDU with multiple TIDs,an equity problem may occur in terms of competition with other wirelesscommunication terminals. Therefore, when the wireless communicationterminal uses the HE MU PPDU in the SU UL transmission, it may be notallowed that the wireless communication terminal transmits the A-MPDUwith multiple TIDs.

FIG. 7 shows that a wireless communication terminal transmits an A-MPDUwith multiple TIDs according to an embodiment of the present invention.

When a wireless communication terminal transmits an HE trigger-basedPPDU or transmits an HE MU PPDU in a DL MU transmission, the wirelesscommunication terminal may transmit a Multi-TID A-MPDU. Also, thewireless communication terminal may transmit a Multi-TID A-MPDUaccording to a certain condition even in SU transmission. Specifically,the wireless communication terminal may transmit the Multi-TID A-MPDUusing the HE MU PPDU. Also, the wireless communication terminal may setthe number of TIDs of the Multi-TID A-MPDU based on the maximum TIDnumber information described above. Specifically, the wirelesscommunication terminal may set the number of TIDs of the Multi-TIDA-MPDU up to the maximum TID number indicated by the maximum TID numberinformation. In the UL transmission, the wireless communication terminalmay obtain the maximum TID number information from the associationresponse frame or the authentication response frame. Also, in the DLtransmission, the wireless communication terminal may obtain the maximumTID number information from the association request frame or theauthentication request frame.

In the embodiment of FIG. 7(a), the non-AP wireless communicationterminal transmits a multi-TID A-MPDU to the AP in the UL SUtransmission. In this case, the non-AP wireless communication terminalobtains the HE Capability information element from the associationresponse (Assoc. Resp.) frame. Also, the non-AP wireless communicationterminal obtains the maximum TID number information from the Max numberof TID field of the HE Capability information element. In this case, themaximum TID number information is 4. Therefore, the non-AP wirelesscommunication terminal transmits the multi-TID A-MPDU having the TIDnumber of 4 (TID 1, TID 3, TID 4, MMPDU) to the AP.

In the embodiment of FIG. 7(b), the AP transmits a multi-TID A-MPDU tothe non-AP wireless communication terminal in the DL SU transmission. Inthis case, the AP obtains the HE Capability information element from theassociation request (Assoc. Req.) Frame. Also, the AP obtains themaximum TID number 4 from the Max number of TID field of the HECapability information element. Therefore, the AP transmits themulti-TID A-MPDU having the TID number of 4 (TID 1, TID 3, TID 4, MMPDU)to the non-AP wireless communication terminal.

FIG. 8 shows a format of a Multi-STA Block ACK frame according to anembodiment of the present invention.

The wireless communication terminal may transmit a Block Ack (BA) frameindicating whether a plurality of MPDUs are received. Also, the wirelesscommunication terminal may transmit a Multi-STA Block ACK (M-BA) frameindicating whether a multi-TID A-MPDU (multi-STA multi-TID A-MPDU,single-STA multi-TID A-MPDU) is received or whether an MPDU (multi-STAsingle TID) corresponding to one TID is received from each of theplurality of wireless communication terminals. The M-BA frame mayinclude a Per AID TID Info subfield indicating whether the reception perAID and the TID is performed.

Specifically, the M-BA frame may include a BA control field. In thiscase, the BA control field may include information on the type andfunction of the BA. In addition, the M-BA frame may include a BAInformation field. The BA Information field may indicate an MPDUindicating whether the BA is received. Also, the BA Information fieldmay indicate whether data is received. Specifically, the BA Informationfield may include a bitmap indicating whether each of the MPDUs or thesequence is received. In this case, the bitmap may be a Block ACK Bitmapfield.

The Block ACK Bitmap field is a bitmap indicating whether data isreceived. A legacy wireless communication terminal may transmit one MSDUin up to 16 fragments. Therefore, the legacy wireless communicationterminal may indicate whether the fragments included in each of 64 MSDUsare received by using the Block ACK Bitmap field having a length of 128bytes. Specifically, the legacy wireless communication terminalallocates 1024 bits of the Block ACK Bitmap field to each fragmentincluded in the MSDU, and sets a bit corresponding to the receivedfragment to 1. The legacy wireless communication terminal may indicatewhether all fragments are received through the block ACK Bitmap field.Therefore, the legacy wireless communication terminal may set theFragment Number field of the Block ACK Starting Sequence Control fieldto the reserved field and may use only the Sequence Number field.

The wireless communication terminal according to the embodiment of thepresent invention may fragment one MSDU into up to four fragments asdescribed above. In addition, the number of fragments that the wirelesscommunication terminal may generate by fragmenting the MSDU variesdepending on the fragmentation level. Therefore, the wirelesscommunication terminal may change the indication method of the Block ACKBitmap field according to the fragmentation level. Specifically, whenthe level of fragmentation applied to the data received by the wirelesscommunication terminal is lower than level 3, the wireless communicationterminal may set each bit of the Block ACK Bitmap field to indicatewhether the MSDU is received. In addition, when the fragmentation levelapplied to the data received by the wireless communication terminal islevel 3, the wireless communication terminal may set each bit of theBlock ACK Bitmap field to indicate whether each of the fragments isreceived.

The BA Information field may include a Block ACK Starting SequenceControl subfield that indicates data indicating whether the Block ACKBitmap field is received. Specifically, the Block ACK Starting SequenceControl subfield may indicate the start number of the data indicated bythe Block ACK Bitmap field. The wireless communication terminal mayindicate whether the bits of the Block ACK Bitmap field are divided intoa sequence unit or a fragment unit through a Block ACK Starting SequenceControl subfield. Specifically, the wireless communication terminal mayset the Least Significant Bit (LSB) of the Fragment Number subfield ofthe Block ACK Starting Sequence Control subfield to 0 to indicate thatthe bits of the Block ACK Bitmap field are divided in sequence units. Inaddition, the wireless communication terminal may set the LSB of theFragment Number subfield of the Block ACK Starting Sequence Controlsubfield to 1 to indicate that the bits of the Block ACK Bitmap fieldare divided in fragment units. Also, the wireless communication terminalmay indicate the length of the Block ACK Bitmap field through the BlockACK Starting Sequence Control subfield. Specifically, the wirelesscommunication terminal may set the values of two bits (LSB+1, LSB+2)following the LSB of the Fragment Number subfield of the Block ACKStarting Sequence Control subfield to indicate the length of the BlockACK Bitmap field. In this case, the number of BA information fieldsincluded in the M-BA frame may be changed according to the number ofwireless communication terminals transmitting data and the TID number.Specifically, the M-BA frame may include a BA Information fieldrepeatedly by a TID number transmitted by a plurality of wirelesscommunication terminals.

As described above, the wireless communication terminal may signal thefragmentation level supported by the wireless communication terminal inthe link setup procedure. Also, the wireless communication terminal maynegotiate the fragmentation level in the ADDBA procedure. In this case,when the recipient supporting the fragmentation level: level 3 does notreceive any MPDU included in the A-MPDU, it is difficult for therecipient to determine in which fragmentation level the originatortransmits the A-MPDU. Therefore, a recipient supporting a fragmentationlevel: level 3 may transmit an M-BA frame including a BA bitmap field,which is divided into fragments, irrespective of the configuration ofthe received A-MPDU.

FIG. 9 shows a method of transmitting an M-BA frame by a wirelesscommunication terminal according to an embodiment of the presentinvention.

As described above, the wireless communication terminal may change thebitmap format indicating whether data is received according to theformat of the received data. When the wireless communication terminalreceives all the MPDUs included in the A-MPDU, the wirelesscommunication terminal may omit a bitmap indicating whether data isreceived in the M-BA frame. In addition, when the wireless communicationterminal receives only one MPDU corresponding to one TID, the wirelesscommunication terminal may omit a bitmap indicating whether data isreceived in the M-BA frame. In addition, when the AP receives all theMPDUs transmitted by the plurality of wireless communication terminals,the wireless communication terminal may omit the bitmap indicatingwhether data is received in the M-BA frame. This is because when thewireless communication terminal receives all the MPDUs included in theA-MPDU or only one single MPDU corresponding to one of the TIDs, thewireless communication terminal may indicate whether the data isreceived even if the bitmap is not used.

Specifically, the wireless communication terminal may set the TID Infosubfield to a predetermined value to indicate that the AP receives allthe MPDUs transmitted by the plurality of wireless communicationterminals. The predetermined value may be 15 (1111_(2b)). In this case,the AP may insert one per AID TID Info subfield in the BA Info field.Specifically, the per AID TID Info subfield may include an AID fieldindicating a wireless communication terminal corresponding to the PerTID Info subfield. In addition, the per AID TID Info subfield mayinclude an ACK type field indicating the type of ACK. In addition, theper AID TID Info subfield may include a TID field indicating the TID ofthe MPDU corresponding to the per AID TID Info subfield. When the APreceives all the MPDUs transmitted by the plurality of wirelesscommunication terminals, the AP may set the AID field of the per AID TIDInfo subfield to an AID indicating a plurality of wireless communicationterminals transmitting data. Also, the AP may insert one per AID TIDInfo subfield and set the AID field of the per AID TID Info subfield toan AID indicating the entire wireless communication terminal. Also, theAP may configure the ACK type of the AID TID Info subfield to indicatethat the bitmap is omitted. Specifically, the AP may set the ACK typefield of the AID TID Info sub field to a predetermined value to indicatethat the BA Starting Sequence Control field and the BA bitmap field areomitted in the BA Information field. In this case, the predeterminedvalue may be 0. In yet another specific embodiment, the AP may omit theper AID TID Info subfield.

In such embodiments, when the TID Info subfield of the M-BA framereceived by the wireless communication terminal is a predeterminedvalue, the wireless communication terminal may determine that the APreceives all the data transmitted from the plurality of wirelesscommunication terminals.

In addition, the wireless communication terminal may set one of thereserved bits of the BA control field to a predetermined value toindicate that the AP receives all the MPDUs transmitted by the pluralityof wireless communication terminals. If one of the reserved bits in theBA control field of the M-BA frame received by the wirelesscommunication terminal is a predetermined value, the wirelesscommunication terminal may determine that the AP receives all the datatransmitted from the plurality of wireless communication terminals.

Through FIGS. 10 to 13 , when the wireless communication terminalreceives all the MPDUs included in the A-MPDU transmitted by any one ofthe wireless communication terminals, a method of transmitting an M-BAframe by a wireless communication terminal will be described.

FIG. 10 shows a method of transmitting an M-BA frame by a wirelesscommunication terminal according to an embodiment of the presentinvention.

When the wireless communication terminal receives all the MPDUs includedin the A-MPDU, the wireless communication terminal may set the ACK typefield of the Per AID TID Info subfield to a predetermined value.Specifically, the wireless communication terminal may set the ACK typefield of the AID TID Info sub field to a predetermined value to indicatethat the BA Starting Sequence Control field and the BA bitmap field areomitted in the BA Information field. In this case, the predeterminedvalue may be 0. In yet another specific embodiment, the predeterminedvalue may be 1. In this case, the wireless communication terminal mayset the TID field of the Per AID TID Info subfield to one of the TIDs ofthe MPDUs receiving the TID field. When the ACK type field value of thePer AID TID Info sub-field of the M-BA frame received by the wirelesscommunication terminal is a predetermined value, the wirelesscommunication terminal may determine that the wireless communicationterminal transmitting the M-BA frame receives all the MPDUs included inthe A-MPDU.

As described above, the wireless communication terminal may transmit theMulti-TID A-MPDU. Also, when the wireless communication terminalreceives not only all the MPDUs included in the A-MPDU but also onesingle MPDU corresponding to any one TID, the wireless communicationterminal may omit the BA Starting Sequence Control field and the BAbitmap field in the BA Information field. However, if the A-MPDUincludes an MPDU corresponding to a TID with an agreement on BA frametransmission and fails to receive even one MPDU in the A-MPDU, thewireless communication terminal may not omit the BA bitmap field in theBA Information field.

If the ACK type field of the Per AID TID Info sub-field of the M-BAreceived by the originator is a predetermined value, it is difficult forthe originator to determine whether the recipient receives all the MPDUsincluded in the A-MPDU or receives a single MPDU corresponding to anyone TID. In the embodiment of FIG. 10(a), the recipient receives allMPDUs and MMPDUs included in the A-MDPU transmitted by originator (AID:1). In this case, the recipient sets the AID field of the Per User Infofield to 1, sets the ACK type field to 0, and sets the TID field to anarbitrary value. Also, in the embodiment of FIG. 10 (b), the recipientreceives only the MPDUs whose TID is 0 among the MPDUs included in theA-MPDU transmitted by the originator (AID: 1). In this case, therecipient sets the AID field of the Per User Info field to 1, sets theACK type field to 0, and sets the TID field to 0. In the embodiment ofFIG. 10(a), when the recipient sets the TID field of the Per User Infofield to 0, the format of the M-BA frame when the recipient receives allthe MPDUs included in the A-MPDU transmitted by the originator and theformat of the M-BA frame when the recipient receives only the MPDU withthe TID value corresponding to 0 are the same.

Therefore, if the wireless communication terminal does not receive anyMPDU included in the A-MPDU, the wireless communication terminal maytransmit a BA Information field including a BA Starting Sequence Controlfield and a BA bitmap field regardless of an agreement on the BA frametransmission. The wireless communication terminal may prevent confusionbetween the case of receiving only one MPDU corresponding to one TID andthe case of receiving all the MPDUs included in the A-MPDU through thisembodiment. In this embodiment, even when the wireless communicationterminal receives an MPDU corresponding to one TID, the wirelesscommunication terminal transmits a bitmap indicating whether data isreceived. Therefore, the M-BA frame transmission efficiency of thewireless communication terminal may be lowered. Therefore, the wirelesscommunication terminal may set the agreed TID for the BA frametransmission to the TID field value of the Per AID TID Info subfield.This will be described in more detail with reference to FIG. 11 .

FIG. 11 shows a method of transmitting an M-BA frame by a wirelesscommunication terminal according to another embodiment of the presentinvention.

When the wireless communication terminal receives all the MPDUs includedin the A-MPDU, the wireless communication terminal may set the ACK typefield of the Per AID TID Info subfield to a predetermined value and setthe agreed TID for BA frame transmission to the TID field value of thePer AID TID Info subfield. If a TID agreed on the BA frame transmissionis provided in plurality, the wireless communication terminal may setthe TID corresponding to the last transmitted MPDU among the pluralityof MPDUs corresponding to the agreed TID for the BA frame transmissionto the TID field value of the Per AID TID Info subfield. In anotherspecific embodiment, when a TID agreed on the BA frame transmission isprovided in plurality, the wireless communication terminal may set theTID field value of the Per AID TID Info subfield based on the userpriority (UP) of the TID. Specifically, the wireless communicationterminal may set the TID having the highest UP to the TID field value ofthe Per AID TID Info subfield. In another specific embodiment, thewireless communication terminal may set the TID having the lowest UPvalue to the TID field value of the Per AID TID Info subfield. In thisembodiment, when there is no TID agreed on the BA frame transmission,even if the wireless communication terminal receives all the MPDUsincluded in the A-MPDU, the wireless communication terminal musttransmit a bitmap indicating whether data is received.

In the embodiment of FIG. 11(a), the recipient receives the A-MDPU fromthe originator with an AID value of 1 and decodes all MPDUs included inthe A-MPDU. In this case, the A-MPDU includes MPDU and MMPDUcorresponding to TID values 0, 2, and 3, respectively. There is anagreement on the BA frame transmission for the TID values 2 and 3between the originator and the recipient, and there is no agreement onthe BA frame transmission for the TID value 1. Therefore, the originatorsets the AID field value of the Per AID TID Info subfield to 1, sets theACK type field to the predetermined value, and sets the TID field valueto 2 or 3 to indicate that all the MPDUs included in the A-MPDUtransmitted by the originator are received. In this case, thepredetermined value indicates that the BA Starting Sequence Controlfield and the BA bitmap field are omitted in the BA Information field asdescribed above. The predetermined value may be 0. In the embodiment ofFIG. 11(b), the recipient receives the A-MDPU from the originator withan AID value of 1 and decodes all MPDUs included in the A-MPDU. In thiscase, the A-MPDU includes only the MPDU corresponding to the TID valueof 2. The originator and the recipient agree on the BA frametransmission for the TID value 2. Therefore, the originator sets the AIDfield value of the Per AID TID Info subfield to 1, sets the ACK typefield to the predetermined value, and sets the TID field value to 2 toindicate that all the MPDUs included in the A-MPDU transmitted by theoriginator are received. In the embodiment of FIG. 11(c), the recipientreceives the A-MDPU from the originator with an AID value of 1 anddecodes all MPDUs included in the A-MPDU. In this case, the A-MPDUincludes MPDU and MMPDU corresponding to TID values 0 and 3,respectively. For the TID values 0 and 3, there is no agreement on theBA frame transmission between the recipient and the originator.Therefore, the recipient transmits the per AID TID Info subfield for TIDvalue 0, the per AID TID Info subfield for TID value 3, and the per AIDTID Info subfield for MMPDU. In this case, the originator sets the TIDfield value of the per AID TID Info subfield for MMPDU to predetermined15 for the MMPDU. In addition, the recipient omits the BA StartingSequence Control field and the BA bitmap field in the BA Informationfield in the per AID TID Info subfield for TID values 0 and 3 not agreedon the BA frame transmission.

In these embodiments, if the ACK type field value of the Per AID TIDInfo sub-field of the M-BA frame received by the wireless communicationterminal is a predetermined value, and the TID field value of the PerAID TID Info subfield is the agreed TID for the BA frame transmission,the wireless communication terminal may determine that the wirelesscommunication terminal transmitting the M-BA frame receives all theMPDUs included in the A-MPDU. In this case, the wireless communicationterminal may determine that the wireless communication terminaltransmitting the M-BA frame receives all the MPDUs included in theA-MPDU, and may stop decoding the M-BA frame.

In another specific embodiment, when the wireless communication terminalreceives all the MPDUs included in the A-MPDU, the TID field value ofthe Per User Info field may be set to a predetermined value. This willbe described with reference to FIG. 12 .

FIG. 12 shows a method of transmitting an M-BA frame by a wirelesscommunication terminal according to another embodiment of the presentinvention.

When the wireless communication terminal receives all the MPDUs includedin the A-MPDU, the wireless communication terminal may set the TID fieldvalue of the Per AID TID Info subfield to a first value. Thepredetermined first value may be a value that is not used as the TIDvalue of the MPDU when the wireless communication terminal transmitsdata. Specifically, the predetermined first value may be any one of8(1000_(2b)) to 14(1110_(2b)). For example, the first value may be 14.

In this embodiment, the wireless communication terminal may set the ACKtype field to a second value to indicate that the BA Starting SequenceControl field and the BA bitmap field are omitted in the BA Informationfield. The predetermined second value may be 0. In yet another specificembodiment, the predetermined second value may be 1. Specifically, whenthe wireless communication terminal receives all the MPDUs included inthe A-MPDU transmitted by any one of the wireless communicationterminals, the wireless communication terminal may set the TID fieldvalue of the Per User Info field to the first value and set the ACK typefield to the second value. Accordingly, when value of the TID field ofthe Per AID TID Info sub-field of the M-BA frame received by thewireless communication terminal is the first value and the ACK typefield value is the second value, the wireless communication terminal maydetermine that the wireless communication terminal transmitting the M-BAframe receives all the MPDUs included in the A-MPDU.

In another specific embodiment, the predetermined first value may be aTID value 15 (1111_(2b)) indicating MMPDU reception. Also, thepredetermined second value may be a value that is not used in the PerAID TID Info subfield indicating whether the MMPDU is received. Forexample, when the ACK type field value used in the Per AID TID Infosubfield indicating whether the MMPDU is received is 0, thepredetermined second value may be 1.

In the embodiment of FIG. 12(a), the recipient receives the A-MDPU fromthe first station STA1 and decodes all the MPDUs included in the A-MPDU.In this case, the A-MPDU includes MPDU and MMPDU corresponding to TIDvalues 1, 2, and 3, respectively. There is no agreement on the BA frametransmission for TID values 1, 2, and 3 between the originator and therecipient. Therefore, the originator sets the AID field value of the PerAID TID Info sub-field to the AID corresponding to the first stationSTA1, sets the ACK type field to 1, and sets the TID field to 14 toindicate that all the MPDUs included in the MPDU transmitted by theoriginator are received. In this case, the ACK type field value 1indicates that the BA Starting Sequence Control field and the BA bitmapfield are omitted in the BA Information field as described above. Also,the TID field value 14 is a predetermined value to indicate that all theMPDUs included in the A-MPDU are received.

In these embodiments, if the ACK type field value of the Per AID TIDInfo sub-field of the M-BA frame received by the wireless communicationterminal is a predetermined first value, the wireless communicationterminal may determine that the wireless communication terminaltransmitting the M-BA frame receives all the MPDUs included in theA-MPDU. Specifically, when the ACK type field value of the Per AID TIDInfo sub-field of the M-BA frame received by the wireless communicationterminal is a predetermined first value, and the TID field value of thePer AID TID Info sub-field is a predetermined second value, the wirelesscommunication terminal may determine that the wireless communicationterminal transmitting the M-BA frame receives all the MPDUs included inthe A-MPDU. In this case, the wireless communication terminal maydetermine that the wireless communication terminal transmitting the M-BAframe receives all the MPDUs included in the A-MPDU, and may stopdecoding the M-BA frame.

Further, when the wireless communication terminal receives the A-MPDUincluding only the MPDU corresponding to the TID not agreed on the BAframe transmission, the wireless communication terminal sets the ACKtype field value of the Per AID TID Info subfield to a value indicatingthat the BA Information field includes the BA Starting Sequence Controlfield and the BA bitmap field, and sets the TID field of the Per AID TIDInfo subfield to the TID not agreed on the BA frame transmission. Thewireless communication terminal does not transmit the BA StartingSequence Control field and the BA bitmap field for the TID not agreed onthe BA frame transmission. Accordingly, the wireless communicationterminal sets the value of the ACK type field to a value indicating thatthe BA Starting Sequence Control field and the BA bitmap field areincluded to indicate that all the A-MPDUs are received. In this case,the A-MPDU may include an MPDU corresponding to a plurality of TIDs notagreed on the BA frame transmission. In this case, the wirelesscommunication terminal may set a TID corresponding to the firsttransmitted MPDU among a plurality of MPDUs corresponding to the TID notagreed on the BA frame transmission to the TID field value of the PerAID TID Info subfield. In another specific embodiment, the wirelesscommunication terminal may configure the TID field value of the Per AIDTID Info subfield based on the User Priority (UP) of the TID.Specifically, the wireless communication terminal may set the TID havingthe highest UP to the TID field value of the Per AID TID Info subfield.In another specific embodiment, the wireless communication terminal mayset the TID having the lowest UP value to the TID field value of the PerAID TID Info subfield. If the A-MPDU includes both an MPDU and an MMPDUcorresponding to a TID not agreed on the BA frame transmission, thewireless communication terminal may set the TID field of the Per AID TIDInfo subfield to 15. In this case, 15(1112b) is a TID field valueindicating that the MMPDU is received as described above.

In the embodiment of FIG. 12(b), the recipient receives the A-MPDU fromthe first station STA1 as in the embodiment of FIG. 12(a). Theoriginator sets the AID field value of the Per AID TID Info subfield tothe AID corresponding to the first station STA1, sets the ACK type fieldwith 0, and sets the TID field to one of the TID values of the MPDUincluded in the A-MPDU to indicate that all the MPDUs included in theA-MPDU transmitted by the originator are received. Specifically, thevalue of the TID field may be 1, 2, 3, or 15 indicating the MMPDU. Inthis case, the ACK type field value 0 indicates that the BA StartingSequence Control field and the BA bitmap field are not omitted in the BAInformation field as described above.

When the ACK type field value of the Per AID TID Info sub-field of theM-BA frame received by the wireless communication terminal is a valueindicating that the BA Information field includes the BA StartingSequence Control field and the BA bitmap field, and the TID field of thePer AID TID Info subfield is a TID not agreed on the BA frametransmission, the wireless communication terminal may determine that thewireless communication terminal transmitting the M-BA frame receives theA-MPDU including only the MPDU corresponding to the TID not agreed onthe BA frame transmission.

FIG. 13 shows a method of transmitting an M-BA frame by a wirelesscommunication terminal according to another embodiment of the presentinvention.

The wireless communication terminal may transmit the BA frame separatelysignaling the MPDU corresponding to the TID agreed on the BA frametransmission and the MPDU corresponding to the TID not agreed on the BAframe transmission. The wireless communication terminal may set the TIDfield value of the Per AID TID Info subfield to a predetermined value toindicate whether all the MPDUs corresponding to the TID agreed on the BAframe transmission among the plurality of MPDUs included in the A-MPDUare received. Specifically, when the wireless communication terminalreceives all the MPDUs corresponding to the TID agreed on the BA frametransmission among the plurality of MPDUs included in the A-MPDU, thewireless communication terminal may set the TID field value of the PerAID TID Info subfield to one of the TIDs agreed on the BA frametransmission regardless of whether the wireless communication terminalreceives an MPDU corresponding to a TID not agreed on the BA frametransmission among a plurality of MPDUs included in the A-MPDU. Inanother specific embodiment, when the wireless communication terminalreceives all the MPDUs corresponding to the TID agreed on the BA frametransmission among the plurality of MPDUs included in the A-MPDU, thewireless communication terminal may set the TID field value of the PerAID TID Info subfield to a predetermined value regardless of whether thewireless communication terminal receives an MPDU corresponding to a TIDnot agreed on the BA frame transmission among a plurality of MPDUsincluded in the A-MPDU. The predetermined value may be a value that isnot used as the TID value of the MPDU when the wireless communicationterminal transmits data. Specifically, the predetermined value may beany one of 8(1000_(2b)) to 14(1110_(2b)). For example, the predeterminedvalue may be 14. Also, when the wireless communication terminal receivesan MPDU corresponding to a TID not agreed on the BA frame transmission,the wireless communication terminal may indicate that the wirelesscommunication terminal receives an MPDU corresponding to a TID notagreed on the BA frame transmission using a Per AID TID Info subfieldother than the Per AID TID Info subfield indicating that all the MPDUscorresponding to the TID agreed on the BA frame transmission arereceived. Specifically, when the wireless communication terminalreceives all the MPDUs corresponding to the TID agreed on the BA frametransmission among the plurality of MPDUs included in the A-MPDU, thewireless communication terminal may indicate that all the MPDUscorresponding to the TID not agreed on the BA frame transmission amongthe MPDUs are received through a separate Per AID TID Info subfield.

In the embodiment of FIG. 13 , the recipient receives the A-MPDU fromthe originator having the AID value of 1 and decodes both the MPDU andthe MMPDU included in the A-MPDU. At this time, the A-MPDU includes MPDUand MMPDU having TID values of 0, 2, and 3 as in the embodiment of FIG.13(a). In addition, the originator and the recipient agreed on a BAframe transmission for TID values 2 and 3 and do not agree on a BA frametransmission for TID value 0. As described above, the recipient sets theTID field value and the ACK type field value of the Per AID TID Infosubfield to indicate that all the MPDUs corresponding to the TID agreedon the BA frame transmission among the MPDUs included in the A-MPDU arereceived. At this time, the recipient may indicate whether the MPDUcorresponding to the TID not agreed on the BA frame transmission isindicated using a separate Per AID TID Info subfield. Specifically, inthe embodiment of FIG. 13(b), the recipient sets the ACK type field ofthe first Per AID TID Info subfield to 0, and sets the TID field to 0 toindicate that the MPDU corresponding to the TID 0 is received. Also, therecipient sets the ACK type field of the second Per AID TID Infosubfield to 0 and sets the TID field to 2 or 3 to indicate that all theMPDUs corresponding to the TID agreed on the BA frame transmission amongthe MPDUs included in the A-MPDU are received. In addition, therecipient sets the ACK type field of the third Per AID TID Info subfieldto 0 and sets the TID field to 15 to indicate that all the MMPDUsincluded in the A-MPDU are received.

In addition, as described above, the recipient may indicate that all theMPDUs corresponding to the TID agreed on the BA frame transmission amongthe MPDUs included in the A-MPDU are received using a separate Per AIDTID Info field. At this time, the recipient may set the TID field of theseparate Per AID TID Info field to a predetermined value. In theembodiment of FIG. 13(c), the recipient sets the ACK type field of thefirst Per AID TID Info subfield to 0 and sets the TID field to14(1110_(2b)) to indicate that all the MPDUs corresponding to the TIDnot agreed on the BA frame transmission among the MPDUs included in theA-MPDU are received. Also, the recipient sets the ACK type field of thesecond Per AID TID Info subfield to 0 and sets the TID field to 2 or 3to indicate that all the MPDUs corresponding to the TID agreed on the BAframe transmission among the MPDUs included in the A-MPDU are received.In yet another specific embodiment, the recipient may set the TID fieldof the separate Per AID TID Info field to one of the TIDs not agreed onthe BA frame transmission. In the embodiment of FIG. 13(d), therecipient sets the ACK type field of the first Per AID TID Info subfieldto 0 and sets the TID field to 0 or 15 to indicate that all the MPDUscorresponding to the TID not agreed on the BA frame transmission amongthe MPDUs included in the A-MPDU are received.

FIG. 14 shows an operation in which a wireless communication terminaltransmits a BSR according to an embodiment of the present invention.

When the wireless communication terminal transmits the trigger-basedPPDU, the wireless communication terminal may transmit the BSR throughthe Duration field of the MAC header. In addition, when the wirelesscommunication terminal transmits an ACK frame using the trigger-basedPPDU, the wireless communication terminal may transmit the BSR throughat least one of the Receiver Address (RA) field and the TransmitterAddress (TA) field of the MAC header. Accordingly, the wirelesscommunication terminal receiving the trigger-based PPDU may obtain theBSR from the Duration field of the MAC header. In addition, the wirelesscommunication terminal receiving the trigger-based PPDU may obtain theBSR from at least one of the Receiver Address (RA) field and theTransmitter Address (TA) field of the MAC header.

Specifically, the AP may trigger the ACK transmission by transmitting ULtrigger information using the trigger frame or the MAC header in the DLtransmission. In this case, the AP may trigger the ACK frametransmission and the BSR transmit together using the indicator of thetrigger frame or the indicator of the UL trigger information. In thiscase, the AP may recognize from which wireless communication terminalthe UL transmission is performed through which Resource Unit (RU). Also,the AP may recognize the duration of the UL transmission. Therefore, theAP may decode the MPDU without the information indicated by the RAfield, the TA field, and the Duration field of the MAC header includedin the UL PPDU. As a result, as described above, when a wirelesscommunication terminal transmits an ACK frame using a trigger-basedPPDU, the wireless communication terminal may transmit the BSR using theDuration field of the ACK frame. In addition, when the wirelesscommunication terminal transmits an ACK frame using the trigger-basedPPDU, the wireless communication terminal may transmit the BSR throughat least one of the RA field and the TA field of the ACK frame. At thispoint, the ACK frame may be a BA frame. Specifically, the ACK frame maybe an M-BA frame. The format of the specific ACK frame may be the sameas that shown in FIG. 14(a). In addition, the format of the concrete BAframe and the M-BA frame may be the same as that shown in FIG. 14(b).

FIG. 15 shows an operation in which a wireless communication terminaltransmits a BSR according to another embodiment of the presentinvention.

The wireless communication terminal may transmit the BSR using the QoSControl field of the ACK frame. In another specific embodiment, thewireless communication terminal may transmit the BSR using the HE-Acontrol field. The wireless communication terminal receiving the ACKframe may obtain the BSR from the QoS Control field. In addition, thewireless communication terminal receiving the ACK frame may obtain theBSR from the HE-A control field.

As described with reference to FIG. 14 , the AP may trigger the ACKframe transmission and the BSR transmission of the wirelesscommunication terminal together. In this case, the wirelesscommunication terminal may transmit the ACK frame by inserting the BSRinto the QoS Control field of the ACK frame. Also, the wirelesscommunication terminal may transmit an ACK frame by inserting the BSRinto the HE-A Control field of the ACK frame. At this point, the ACKframe may be a BA frame. Specifically, the ACK frame may be an M-BAframe. The format of the specific ACK frame may be the same as thatshown in FIG. 15(a). In addition, the format of the concrete BA frameand the M-BA frame may be the same as that shown in FIG. 15(b).

FIG. 16 shows an operation in which a wireless communication terminaltransmits a BSR according to another embodiment of the presentinvention.

The wireless communication terminal may transmit the BSR using the BAInfo field of the M-BA frame. Specifically, the wireless communicationterminal may insert a BA Info field for BSR transmission into an M-BAframe. In a specific embodiment, the wireless communication terminal mayinsert a BA Info field for BSR transmission after the BA Info fieldcorresponding to the TID receiving the data in the M-BA frame. Also, thewireless communication terminal may set the TID field of the BA Infofield to a predetermined value to indicate that the corresponding BAInfo field is for BSR transmission. In this case, the predeterminedvalue may be a TID value which is not used for data transmission.Specifically, the predetermined value may be any one of 8(1000_(2b)) to15(1111_(2b)). Also, the wireless communication terminal may transmitthe BSR using the BA Ack sequence control and the BA bitamp subfield inthe BA Info field. In this case, the wireless communication terminal mayset the ACK type field to a value indicating that a Block Ack sequencecontrol and a BA bitamp subfield present. The format of the specificM-BA frame may be the same as that shown in FIG. 16 .

The wireless communication terminal receiving the M-BA frame may obtainthe BSR from the BA Info field. The wireless communication terminalreceiving the M-BA frame may obtain the BSR from the last BA Info field.

FIG. 17 shows an operation in which a wireless communication terminaltransmits a BSR according to an embodiment of the present invention.

The wireless communication terminal may transmit the QoS Null MPDUincluding the ACK frame and the BSR using the A-MPDU. Specifically, whenthe size of the RU allocated to the wireless communication terminal islarger than a certain reference, the wireless communication terminal maytransmit the QoS Null MPDU including the ACK frame and the BSR using theA-MPDU. In another specific embodiment, if the size of the informationto be transmitted by the BSR is greater than a certain reference, thewireless communication terminal may transmit the QoS Null MPDU includingthe ACK frame and the BSR using the A-MPDU. In addition, the wirelesscommunication terminal may transmit an ACK frame and a plurality of QoSnull MPDUs using the A-MPDU. The wireless communication terminalreceiving the A-MPDU including the ACK frame may obtain the QoS NullMPDU including the BSR from the A-MPDU.

Also, the ACK frame transmitted by the wireless communication terminalmay be an M-BA frame. The specific format of the A-MPDU transmitted bythe wireless communication terminal may be the same as that shown inFIG. 17 .

FIG. 18 shows the operation of a wireless communication terminalaccording to an embodiment of the present invention.

The originator 1801 transmits the A-MPDU to the recipient 1803 (S1801).In this case, the A-MPDU may include a plurality of MPDUs correspondingto a plurality of different TIDs. Specifically, the A-MPDU may be theMulti-TID A-MPDU described above. In addition, a plurality oforiginators 1801 may simultaneously transmit the A-MPDU to the recipient1803.

The recipient 1803 transmits an ACK to the originator 1801 based on thereceived A-MPDU (S1803). When the recipient 1803 receives all the MPDUsincluded in the A-MPDU, the recipient 1803 may transmit a BA framesignaling that all MPDUs included in the A-MPDU are received without abitmap indicating whether each MPDU included in the A-MPDU is received.Specifically, the recipient 1803 may transmit a BA frame by inserting aPer AID TID Info field indicating that all the MPDUs included in theA-MPDU received from the originator 1801 are received into the BA frame.Also, the recipient 1803 may set a predetermined first value in thetraffic identifier (TID) field of the BA frame when transmitting the BAframe. In this case, the TID field is for indicating the TID of theMPDU, in which whether the MPDU is received is indicated by the BAframe. The predetermined first value may be a value that is not used asa TID value when transmitting data. Specifically, the predeterminedfirst value may be any one of 8(1000_(2b)) to 14(1110_(2b)). Forexample, the predetermined first value may be 14. In another specificembodiment, the predetermined first value may be a TID value 15(1111_(2b)) indicating MMPDU reception.

When the recipient 1803 transmits a BA frame signaling that all MPDUsincluded in the A-MPDU are received, the recipient 1803 may omit thestart sequence control field. The start sequence control field is forindicating a MPDU, in which whether the MPDU is received is indicated bythe bitmap. In this case, the start sequence control field may be theBlock ACK Starting Sequence Control field described above. Specifically,when the recipient 1803 transmits a BA frame signaling that all theMPDUs included in the A-MPDU are received, the recipient 1803 mayindicate that the BA frame does not include a bitmap and a startsequence control field by setting the value of the ACK type fieldindicating the type of ACK to a predetermined second value.

Also, when the value of the TID field of the BA frame received by theoriginator 1801 is a predetermined first value, the originator 1801 maydetermine that the BA frame indicates that the recipient 1803 receivesall the MPDUs included in the A-MPDU without a bitmap indicating whethereach MPDU included in the A-MPDU is received. In this case, the TIDfield is for indicating the TID of the MPDU, in which whether the MPDUis received is indicated by the BA frame. Specifically, when the valueof the TID field of the BA frame received by the originator 1801 is apredetermined first value and the value of the ACK type field of the BAframe is a predetermined second value, the originator 1801 may determinethat the BA frame indicates that the recipient 1803 receives all theMPDUs included in the A-MPDU without a bitmap indicating whether eachMPDU included in the A-MPDU is received. In addition, when the value ofthe TID field of the BA frame received by the originator 1801 is apredetermined first value, the originator 1801 may stop decoding thecorresponding BA frame.

In another specific embodiment, when the recipient 1803 transmits a BAframe signaling that all A-MPDUs are received, the ACK type fieldindicating the type of ACK in the BA frame may be set to a predeterminedvalue, and the TID value agreed on the BA frame transmission betweenoriginator 1801 and recipient 1803 may be set to the TID field of the BAframe. When a TID agreed on for BA frame transmission between originator1801 and recipient 1803 is provided in plurality, the recipient 1803 mayset the TID corresponding to the last transmitted MPDU among theplurality of MPDUs corresponding to the agreed TID for the BA frametransmission to the TID field value of the Per AID TID Info subfield. Inanother specific embodiment, when a TID agreed on the BA frametransmission is provided in plurality, the recipient 1803 may set theTID field value of the Per AID TID Info subfield based on the userpriority (UP) of the TID. Specifically, the recipient 1803 may set theTID having the highest UP to the TID field value of the Per AID TID Infosubfield. In another specific embodiment, the recipient 1803 may set theTID having the lowest UP value to the TID field value of the Per AID TIDInfo subfield.

Also, when the value of the ACK type field of the BA frame is apredetermined value, and the value of the TID field is the TID agreed onthe BA frame transmission between the originator 1801 and the recipient1803, the originator 1801 may determine that the BA frame indicates thatthe recipient 1803 receives all the MPDUs included in the A-MPDU withouta bitmap indicating whether each MPDU included in the A-MPDU isreceived.

The recipient 1803 may transmit the BA frame separately signaling theMPDU corresponding to the TID agreed on the BA frame transmission andthe MPDU corresponding to the TID not agreed on the BA frametransmission. The recipient 1803 may set the TID field value of the PerAID TID Info subfield to a predetermined value to indicate whether allthe MPDUs corresponding to the TID agreed on the BA frame transmissionamong the plurality of MPDUs included in the A-MPDU are received.Specifically, when the recipient 1803 receives all the MPDUscorresponding to the TID agreed on the BA frame transmission among theplurality of MPDUs included in the A-MPDU, the recipient 1803 may setthe TID field value of the Per AID TID Info subfield to one of the TIDsagreed on the BA frame transmission regardless of whether the recipient1803 receives an MPDU corresponding to a TID not agreed on the BA frametransmission among a plurality of MPDUs included in the A-MPDU. Inanother specific embodiment, when the recipient 1803 receives all theMPDUs corresponding to the TID agreed on the BA frame transmission amongthe plurality of MPDUs included in the A-MPDU, the recipient 1803 mayset the TID field value of the Per AID TID Info subfield to apredetermined value regardless of whether the recipient 1803 receives anMPDU corresponding to a TID not agreed on the BA frame transmissionamong a plurality of MPDUs included in the A-MPDU. The predeterminedvalue may be a value that is not used as the TID value of the MPDU whenthe wireless communication terminal transmits data. Specifically, thepredetermined value may be any one of 8(1000_(2b)) to 14(1110_(2b)). Forexample, the predetermined value may be 14. Also, when the recipient1803 receives an MPDU corresponding to a TID not agreed on the BA frametransmission, the recipient 1803 may indicate that the recipient 1803receives an MPDU corresponding to a TID not agreed on the BA frametransmission using a Per AID TID Info subfield other than the Per AIDTID Info subfield indicating that all the MPDUs corresponding to the TIDagreed on the BA frame transmission are received. Specifically, when therecipient 1803 receives all the MPDUs corresponding to the TID agreed onthe BA frame transmission among the plurality of MPDUs included in theA-MPDU, the recipient 1803 may indicate that all the MPDUs correspondingto the TID not agreed on the BA frame transmission among the MPDUs arereceived through a separate Per AID TID Info subfield.

In addition, when the TID field value of the Per AID TID Info subfieldof the BA frame received by the originator 1801 is a predeterminedvalue, the originator 1801 may determine that the recipient 1803receives all the MPDUs corresponding to the TID agreed on the BA frametransmission among the plurality of MPDUs included in the A-MPDU.

In addition, the recipient 1803 may set the ID Info subfield to apredetermined value to indicate that all the data transmitted by theplurality of originators 1801 is received. The predetermined value maybe 15 (1111_(2b)). In this case, the recipient 1803 may insert one perAID TID Info subfield in the BA Info field. When the recipient 1803receives all the MPDUs transmitted by the plurality of originators 1803,the recipient 1803 may set the AID field of the per AID TID Infosubfield to an AID indicating a plurality of wireless communicationterminals transmitting data. Also, the recipient 1803 may insert one perAID TID Info subfield and set the AID field of the per AID TID Infosubfield to an AID indicating the entire wireless communicationterminal. In this case, the entire wireless communication terminal mayindicate all the wireless communication terminals included in the sameBSS as the recipient 1803. Also, the recipient 1803 may set the ACK typeof the AID TID Info sub-field to a predetermined value to indicate thatthe bitmap is omitted. Specifically, the recipient 1803 may set the ACKtype field of the AID TID Info sub field to a predetermined value toindicate that the BA Starting Sequence Control field and the BA bitmapfield are omitted in the BA Information field. In this case, thepredetermined value may be 0. In yet another specific embodiment, therecipient 1803 may omit the per AID TID Info subfield.

The specific operation of the recipient 1803 related to the BA frametransmission may be the same as that of the embodiments described withreference to FIGS. 9 to 13 . In addition, the specific operation of theoriginator 1801 related to the reception of the BA frame may be the sameas that of the embodiments described with reference to FIGS. 9 to 13 .

In addition, the recipient 1803 may transmit the BSR together whentransmitting the ACK frame. In this case, the ACK frame may include a BAframe, and the ACK frame may be an M-BA frame. Specifically, when therecipient 1803 transmits the trigger-based PPDU, the recipient 1803 maytransmit the BSR using the Duration field of the MAC header. Inaddition, when the recipient 1803 transmits an ACK frame using thetrigger-based PPDU, the recipient 1803 may transmit the BSR using atleast one of the Receiver Address (RA) field and the Transmitter Address(TA) field of the MAC header. In another specific embodiment, therecipient 1803 may transmit the BSR using the QoS Control field of theACK frame. In another specific embodiment, the recipient 1803 maytransmit the BSR using the HE-A control field. In another specificembodiment, the recipient 1803 may transmit the BSR using the BA Infofield of the M-BA frame. In another specific embodiment, the recipient1803 may transmit a QoS Null MPDU including an ACK frame and a BSR usingan A-MPDU. The specific operation of the recipient 1803 and originator1801 may be the same as that of the embodiments described with referenceto FIGS. 14 to 17 .

Although the present invention is described by using wireless LANcommunication as an example, it is not limited thereto and may beapplied to other communication systems such as cellular communication.Additionally, while the method, device, and system of the presentinvention are described in relation to specific embodiments thereof,some or all of the components or operations of the present invention maybe implemented using a computer system having a general purpose hardwarearchitecture.

The features, structures, and effects described in the above embodimentsare included in at least one embodiment of the present invention and arenot necessary limited to one embodiment. Furthermore, features,structures, and effects shown in each embodiment may be combined ormodified in other embodiments by those skilled in the art. Therefore, itshould be interpreted that contents relating to such combination andmodification are included in the range of the present invention.

While the present invention is described mainly based on the aboveembodiments but is not limited thereto, it will be understood by thoseskilled in the art that various changes and modifications are madewithout departing from the spirit and scope of the present invention.For example, each component specifically shown in the embodiments may bemodified and implemented. It should be interpreted that differencesrelating to such modifications and application are included in the scopeof the present invention defined in the appended claims.

The invention claimed is:
 1. A wireless communication terminal that is arecipient for receiving data, the wireless communication terminalcomprising: a transceiver; and a processor, wherein the processor isconfigured to: receive an Aggregate-MAC Protocol Data Unit (A-MPDU) froman originator using the transceiver, when generating a block ACK (BA)frame to indicate that all MPDUs in the A-MPDU are received, set a valueof a traffic identifier (TID) field of the BA frame, usable forindicating a TID of a MPDU to be acknowledged in the BA frame, to apredetermined first value and a value of an ACK type field of the BAframe to a predetermined second value, omit a bitmap indicating whethereach MPDU included in the A-MPDU is received in the BA frame, and omit aBlock ACK Starting Sequence Control field in the BA frame, wherein thepredetermined first value is predetermined for indicating that all MPDUsin the A-MPDU are received, is a value that cannot be used as a value ofTID of traffic of data transmission, and is limited to one of 8 to 14and not 15 which indicates management MPDU (MMPDU), wherein thepredetermined second value of the ACK type filed signals that the bitmapand Block ACK Starting Sequence Control field are omitted, and transmitto the originator the BA frame using the transceiver.
 2. The wirelesscommunication terminal of claim 1, wherein the A-MPDU includes aplurality of MPDUs corresponding to a plurality of different TIDs.
 3. Awireless communication terminal that is an originator for transmittingdata, the wireless communication terminal comprising: a transceiver; anda processor, wherein the processor is configured to: transmit anAggregate-MAC Protocol Data Unit (A-MPDU) to a recipient using thetransceiver, receive a block ACK (BA) frame from the recipient using thetransceiver, wherein the BA frame includes a traffic identifier (TID)field usable for indicating a TID of a MPDU to be acknowledged in the BAframe, and when a value of the TID field of the BA frame is apredetermined first value and a value of an ACK type field of the BAframe is a predetermined second value, determine that the BA frameindicates that all MPDUs included in the A-MPDU are received and doesnot include a bitmap indicating whether each MPDU included in the A-MPDUis received, wherein the predetermined first value is predetermined forindicating that all MPDUs in the A-MPDU are received, is a value thatcannot be used as a value of TID of traffic of data transmission, and islimited to one of 8 to 14 and not 15 which indicates management MPDU(MMPDU).
 4. The wireless communication terminal of claim 3, wherein theprocessor is configured to determine that the BA frame does not includea Block ACK Starting Sequence Control field when the value of the TIDfield of the BA frame is the predetermined first value and the value ofthe ACK type field of the BA frame is the predetermined second value. 5.The wireless communication terminal of claim 3, wherein the A-MPDUincludes a plurality of MPDUs corresponding to a plurality of differentTIDs.
 6. An operation method of a wireless communication terminal thatis a recipient for receiving data, the method comprising: receiving anAggregate-MAC Protocol Data Unit (A-MPDU) from an originator; and inresponse to the A-MPDU, generating a block ACK (BA) frame to indicatethat all MPDUs in the A-MPDU are received, wherein the generating the BAframe comprises: setting a value of a traffic identifier (TID) field ofthe BA frame, usable for indicating a TID of a MPDU to be acknowledgedin the BA frame, to a predetermined first value and a value of an ACKtype field of the BA frame to a predetermined second value to signalthat all MPDUs included in the A-MPDU are received, and omitting abitmap indicating whether each MPDU included in the A-MPDU is receivedin the BA frame, wherein the predetermined first value is predeterminedfor indicating that all MPDUs in the A-MPDU are received, is a valuethat cannot be used as a value of TID of traffic of data transmission,and is limited to one of 8 to 14 and not 15 which indicates managementMPDU (MMPDU), and transmitting to the originator the BAframe.
 7. Theoperation method of claim 6, wherein when the generating the BA framefurther comprises omitting a Block ACK Starting Sequence Control fieldin the BA frame.
 8. The operation method of claim 6, wherein the A-MPDUincludes a plurality of MPDUs corresponding to a plurality of differentTIDs.